How should the conservative movement evolve?

That was the question debated last night by two of conservatism’s smartest and most thoughtful public intellectuals — Tevi Troy and Peter Wehner — at the American Enterprise Institute. The event proved to be as much a discussion as a debate, and was no worse for that.

The moderator, the estimable Ramesh Ponnuru, fairly summed up the two postions as follows: Troy was arguing more for a recalibration of conservatism; Wehner more for a revision, though not at the core.

Wehner pointed to the changing demographic make-up of the electorate. He noted that had Mitt Romney run in the context of the 1980 electorate, and done as well as he did in 2012 with each major demographic group, he would have outpolled Ronald Reagan. Conservatives, he warned, cannot consistently win elections with arguments geared to an electorate that no longer exists.

Troy warned that Republicans/conservatives must be true to their base. The message can be stated better and the issue mix can be fine-tuned, with some matters emphasized more and some less. But, Troy insisted, a party that abandons its principles to win elections will end up with neither principles nor victories.

Wehner looked to past instances where revision, or at least serious recalibration, produced victory. In the U.S., he cited Bill Clinton’s moderation of hard-core liberalism and George W. Bush’s compassionate conservatism. He also cited Tony Blair’s success in remaking Britain’s Labour Party.

Wehner maintains that the key to success is a leader whom the base trusts sufficiently on core matters to permit him to revise around the edges. Pete may have had Marco Rubio in mind. Clearly, he has immigration reform in mind as an issue where conservative revisionism is required.

For me, Clinton and Bush show how factors other than trust can determine the success of revisionism. Clinton succeeded in toning down Democratic liberalism not because he had a storehouse of trust, but because the Democrats were sick of losing and because he was slick.

Bush too lacked a high level of natural trust from the base. In my view, his compassionate conservatism gained acceptance in part because Republicans had just lost two presidential elections to a guy who oozed compassion and in part because the only serious opposition to Bush came from the center in the form of John McCain.

In 2016 and beyond, there will be serious opposition from the right to any Republican who strays significantly from the traditional message. Amnesty for illegal immigrants will likely be viewed as such straying. Certainly, that was the case in 2012. Just ask Rick Perry.

On a positive note, both speakers believe that, even with demography on their side, the Democrats face major problems going forward. Liberalism (or progressivism, if you prefer) is intellectually tired and, so to speak, financially broke. Pete suggested that it would not be difficult for conservatives persuasively to organize around the theme of “modernization” — of entitlements, of immigration, of education, etc.

I wonder whether liberals see the land mines ahead for them with the same clarity that conservatives like Tevi and Pete see ours. And I wonder whether they are having the kind of useful debates that AEI put on last night.